Screw driver



July 7, 1936. H F. PHILLIPS ET AL 2,046,840

SCREW DRIVE R Filed Jan. 15, 1935 HENRY FT PH LL/F'J '3 THOMAS M. F'/7'2FA7'R/CK IN VENTOR.

( ATTORNEYS.

Patented July 7, 1936 UNITED STATES 2,046,840 PATENT OFFICE.

SCREW DRIVER Henry F. Phillips, Piedmont, Calif., and Thomas M. Fitzpatrick, New York, N. Y., assignors to Phillips Screw Company, Wilmington, Del. Application January 15, 1935, Serial No. 1,94:

10 Claims. (01. 145-50 at one of its ends with a bit of special conflgura- I tion to fit precisely within a recess of correspond-' ing shape formed in the head of all sizes of screws for driving the same. The invention also embraces the production of punches for punching the recesses in said screws and we, therefore,

do not wish to be limited merely to screw drivers.

Hitherto the manufacture of screws with a cruciform or other shape of aperture has been impractical, 'several proposed types requiring:

9 casting, which is so expensive as to make manufacturing costs prohibitive. Other types require broaching, but tliis operation pushes the metal ahead of the tool, and so disturbs the distribution of metal as to render the screw head extremely fragile.

Ordinary screws are cut, rolled or stamped by automatic machinery and cost but a few cents per hundred to produce. It is, therefore, one of the principal objects of the present invention to provide a tool which may be used with automatic machinery to punch recesses in the heads of screws in such a way that all of the desirable virtues of the screw head and the recesses therein are retained, and which results 35 in certain additional advantages, namely, the screw headis left stronger near the outer edge than heretofore possible, the recess firmly and accurately receives the driver, and causes the driver to centralize itself with respect to the 4:) screw head.

Moreover, the new and novel construction of our tool produces a screw driver having substantial core portion with equally strong radiating vanes or gripping surfaces for engagement with 5 the grooved portions of the recess in the screw head. Thus we provide a tool of maximum strength and at the same time one which when used as a punch, forms a punched recess in a 50 most efiicient manner, by permitting the proper flow and distribution of the metal without causing any of the disadvantages as above pointed out in reference to other types of punches, broaches and the like.

55 These and other objects will appear as our invention is more fully hereinafter described in the following specification, illustrated in the accompanying drawing and finally pointed out in the appended claims.

60 In the drawing:

Figure 1 is a side elevation of our new and improved form of screw driver.

Figure 2 is an enlarged fragmentary view of the lower end of Figure 1 with the tool rotated through 45 degrees of a circle. 5

Figure 3 is an end elevation of Figure 2.

Figure 4 is a'sectional view taken on the line 4-4 of Figure 2.

Figure 5 is a sectional side elevation of Figure 3 taken on the line 55 of Figure 3. 10

Figure 6 is a side elevation of a modified form of tool. I

Figure 7 is an enlarged fragmentary view of the lower end of the tool shown in Figure 6 with the same rotated through 45 degrees of a circle. 15

Figure 8, is an end elevation of Figure '7. Referring now more particularly to the draw- Reference numeral l indicates the shank of the tool which is provided at one of its ends 20 with any suitable form of gripping means, such for instance, as a handle 2, or this end of the shank may be formed into any suitable shape to provide gripping means for operative engagement with a. power driven tool, or the same may 5 be adapted for engagement with punching machinery when the tool is to be used as a punch. -The opposite or front end of the shank, as shown in Figures 1 to 4, is formed with a bit including a plurality of flutes or recesses generally indicated at 3, which preferably originate at. equidistant points 4 on the surface of the shank. The bit is generally polygonal in horizontal cross-section, that is, transversely of the axis of the bit. The outeredges of the flutes diverge from their points of origin toward the lower end of the bit. Those portions of the shank intermediate the edges of the flutes converge into vanes 5 which are formed with flat tapered side walls 6 and an outer wall, the front surface i of which, inclines inwardly toward the axis of the bit. The inclined portions! of the outer walls of the vanes form the front endsof the vanes. By reason of the tapering side walls 6, it will be seen that the vanes are of gradually increasing thickness from their outer edges toward the axis of the bit which produces a strong construction and obviates any danger of breaking the vane by any side loads thrust thereagainst. The lower or front ends of the vanes taper from points 8 on the surface of the shank to diametrically opposed points 9 around the longitudinal axis of the shank. That is, the thickness of each vane gradually increases from the surface 1 rearwardly in a direction longitudinally of the bit. The area between the points 9 may be regarded as the core, and it is of vital importance to the successful operation of the tool, either as a punch or as a screw driver, that the core portion be as w large and strong as poasihleand atthe same time allow suiflcient depth to the flutes, and radial dimensions to the vanes. The lulu-most end or the core portion may be dthafiat, pointed, or rounded. Theparticularshapeiaimnnterial so long as ablunt anddurahleendia luvlded.

The bottomsurfaceofeachfinteureeessi is generally concave and mergs with the side walls of the two adjacent vanes. 81th bottom surface may comprise apluralityotconflgnmaswalls it which merge at an angle with the bottom edges ofthe iiattaperingsidewallaidthevanesi, as shown in Figurm'a, 3,and4,m'snehbottom surfaces maybemadeconeaveoran'vedasshown in Figures 7 and 8. Ineltherfmn, however, the proper size or sectional area of the core portion must be maintained andthevanesnmstbe formed with tapering side walls, as abuse printed out, which merge with the both'am of the flutes or recesses.

With either form of tool when and as a punch with the usual automatic machinery, recesms may be quickly and accurately formed in blank screw heads without flrstformingapibtholgorother opening therein, to be enlarged by theinwardthnistofthemaslstheoustomary practice in punching-memo! certain other types.

We claim:

LAtoolhavingaslnnkandaliLsaldbit in of n rally polraonai n in horizontal cross-section and a plurality of screw e vans amed longitudinally of the bitandutmdmg ndlanyofthe axis thereofrt lof saidvanesbelngdgradually increasing thickness in hcrimntal emu-section from the outeredgethemottowardtheaakof the bit, and each vane having an outcwall which inclines inwardly toward the axis d the bit.

2. A toolhavingashank lovidedwithabitat the front end thereof, said at hdng at polygonal configuration in hia'llntal M- 3.Atoolhavimadlank awldedwlthabit at its front end,saidlitbdmdmllypolygonal configurationinhmimhlcm-aection, saidbitcomprinngaplunllyotradiallyarranged vanes, eachvanelmvhaganouter whichinclines towardtheaaiadfln thebit,andeachvanealmhelmdanihmllyincreasing thickness in section from thefrontendtowardfllerearthueod.

4. A toolhavingaai'nnklluvldedwithabit at its front end, said bitbelngd gmerallymnal configuration in horilmtal m said bit comprising a pluralityotrldially-arrangedva'nes andafluteorrecessbetiemeadatwnadjaeept vanes. eachvanehavinganoda-Iallthefl'ont portion of which inclinm innrdly toward the aaisofthebiteachctsaidvansheimotgradually increasing thickness in holianntal crosssectionfromtheouterubethnedtonrdthe axis of the bit, each of said recesses being generally concave in form and each having the bottom wall thereof merging with the side walls of two adjacent vanes.

5. A tool as claimed in claim 4, wherein the said recesses between the vanes are generally concave in form and each comprising a plurality of contiguous walls.

6. A tool comprising a shank and a bit, said bit being of generally polygonal configuration in horizontal cross section and comprising a plurality of tapered screw engaging vanes, each vane having fiat tapered side walls and a tapered outer wall, the recesses between said vanes being generally concave and comprising a plurality of contiguous walls intermediate the vanes, the said contiguous walls merging at an angle with the edges of said side walls of the vanes and being formed of a plurality of angularly disposed faces.

71 A tool comprising a shank and a bit, said bit being of generally polygonal configuration in horizontal cross section and comprising a plurality of tapered screw engaging vanes, each vane having fiat tapered side walls and a tapered outer wall, the recesses between said vanes being generally concave and comprising a plurality of contiguous walls intermediate the vanes, the said contiguous walls merging at an angle with the edges of said side walls of the vanes and being formed of a plurality of angularly disposed faces, and the lowermost end of the bit being substantially convex in form.

8. A tool comprising a shank and a bit, said bit being of generally square configuration in horizontal cross section and comprising a plurality of equidistant and diametrically opposed tapered screw engaging vanes, each vane having fiat tapered side walls and a tapered outer wall, the recesses between said vanes being generally concave and comprising a plurality of contiguous walls intermediate the vanes, the said contiguous walls merging at an angle with the edges of said side walls of the vanes and being formed of a plurality of angularly disposed faces.

9. A tool comprising a shank and a bit, said bit being of substantially square configuration in horizontal cross section and comprising four equidistant and diametrically opposed tapered screw engaging vanes, each vane having flat tapered side walls and a tapered outer wall, the between said vanes being generally concave and comprising a plurality of contiguous walls intermediate the vanes, the said contiguous walls merging at an angle with the edges of said side walls of the vanes and being formed of a plurality oi angularly disposed faces.

10. A tool comprising a cylindrical shank having gripping means secured to one of its ends and its opposite end formed with a plurality of flutes, said flutes originating at equidistant points on the surface of the shank spaced from the end of the tool and diverging toward the end of the tool, the side and bottom walls of said flutes comprising a plurality of angular smooth-faced surfaces extending from said points of origin of the fiutes to the ends thereof, the adjacent side walls of said flutes uniting into vanes whose outer walls taper from said equidistant surface points to equidistant points adJacent the end of the tool, the lower ends of said vanes being inclined toward the longitudinal axis of the shank.

HENRY F. PHIILIPS. THOMAS M. FI'IZPA'IRICK. 

